CO2 capture during compressed air energy storage

Abstract

A compressed air energy storage system and method of capturing CO 2 during compressed air energy storage the system and method including a gas inlet pipe, at least one air compressor stage attached to the gas inlet pipe and adapted for compression of a gas, a heat transfer system to cool the gas during or after compression, the heat being recycled throughout the system, at least one absorption bed for separating CO 2 from the compressed gas attached to the heat transfer system, at least one compressed gas reservoir having an inlet and an outlet, the reservoir attached at its inlet to the absorption bed, at least one preheater stage attached to the outlet of the compressed gas reservoir for heating a compressed gas after storage in the compressed gas reservoir, and at least one gas expander attached to the preheater stage and adapted for the expansion of the compressed gas.

1. A compressed air energy storage system comprising: a gas inlet pipe;
 at least one air compressor stage attached to and located downstream from the gas inlet pipe, the at least one air compressor stage being adapted for compression of a gas; 
 a heat transfer system linked to and located downstream from the at least one air compressor stage; 
 at least one absorption bed linked to and located directly downstream from the heat transfer system; 
 at least one compressed gas reservoir having an inlet and an outlet, the inlet of the compressed gas reservoir being attached to an outlet of the absorption bed; 
 at least one preheater that is attached to the outlet of the compressed gas reservoir, the at least one preheater adapted to heat a compressed gas before expansion but after storage in the compressed gas reservoir; and 
 at least one gas expander that is linked to and located directly downstream from the at least one preheater and is adapted for the expansion of the compressed gas, 
 wherein the heat transfer system being adapted (1) to remove at least a portion of heat from the gas during or after compression and (2) to recycle at least a portion of the removed heat to heat the at least one absorption bed, and/or to preheat a compressed gas prior to expansion with the removed heat, and/or to heat the expanded gas after each stage of expansion with the removed heat. 
 
     
     
       2. The compressed air energy system according to  claim 1 , wherein the gas inlet pipe is attached to the exhaust stream of an oil fired power plant or a coal fired power plant or a gas turbine power plant. 
     
     
       3. The compressed air energy system according to  claim 1 , further comprising a gas storage tank, wherein the gas storage tank is attached to the gas inlet pipe. 
     
     
       4. The compressed air energy system according to  claim 1 , further comprising a dryer, wherein the inlet of the dryer is attached to and located directly downstream from the outlet of the at least one air compressor stage and the outlet of the dryer is attached to and located directly upstream from the heat transfer system, wherein the dryer contains a desiccant selected from the group consisting of activated alumina, silica gel and molecular sieve zeolites. 
     
     
       5. The compressed air energy storage system of  claim 1 , wherein the heat transfer system comprises at least one heat exchanger that cools the gas during compression and heats the gas during expansion. 
     
     
       6. The compressed air energy system according to  claim 1 , wherein the heat transfer system further comprises:
 at least one heat accumulator for storing heat removed from the compressed gas. 
 
     
     
       7. The compressed air energy system according to  claim 1 , wherein the at least one absorption bed is a pressure swing absorption bed, a temperature swing absorption bed, or a pressure and temperature swing absorption bed. 
     
     
       8. The compressed air energy system according to  claim 1 , wherein the at least one absorption bed contains a CO 2  absorbent selected from the group consisting of monoethanolamine, diethanolamine, methyl-diethanolamine, zeolites, molecular sieves and metal-organic frameworks. 
     
     
       9. The compressed air energy system according to  claim 1 , further comprising a storage reservoir or processing apparatus linked to and located directly downstream from the at least one absorption bed for the component absorbed from the gas. 
     
     
       10. The compressed air energy system according to  claim 1 , wherein the compressed gas reservoir is selected from a group consisting of a cavern, a cave, an aquifer, a mine, and other geologic formations. 
     
     
       11. The compressed air energy system according to  claim 1 , wherein the gas expander comprises a turbine. 
     
     
       12. The compressed air energy system according to  claim 11 , wherein the at least one preheater comprises:
 at least one heat exchanger for heating the compressed gas prior to entering the turbine, and for using the expanded gas to cool the at least one absorption bed. 
 
     
     
       13. A method of capturing CO 2  during compressed air energy storage, comprising:
 compressing a gas in at least one compression stage; 
 removing at least a portion of heat from a compressed gas during or after the at least one compression stage; 
 separating CO 2  from the compressed gas using an absorption bed after the removal of heat through a heat transfer system linked to and located downstream from the at least one compression stage; 
 storing the compressed gas in a compressed gas reservoir after separating CO 2  from the compressed gas; 
 subsequently removing the stored gas from the compressed gas reservoir and then expanding the compressed gas while deriving work from the gas; 
 preheating the compressed gas prior to expansion by feeding the compressed gas through at least one heat exchanger; and 
 recycling at least a portion of the removed heat from the heat transfer system to preheat the compressed gas prior to expansion, and/or to heat the expanded gas after each stage of expansion with the removed heat, and/or to heat the absorption bed with the removed heat. 
 
     
     
       14. The method of capturing CO 2  during compressed air energy storage according to  claim 13 , wherein the heat removed from the compressed gas is stored in a heat accumulator. 
     
     
       15. The method of capturing CO 2  during compressed air energy storage according to  claim 13 , further comprising separating condensed water from the compressed gas after cooling the gas; wherein the condensed water is removed using a dryer. 
     
     
       16. The method of capturing CO 2  during compressed air energy storage according to  claim 13 , wherein the CO 2  is separated using a pressure swing absorption bed, a temperature swing absorption bed, or a pressure and temperature swing absorption bed. 
     
     
       17. The method of capturing CO 2  during compressed air energy storage according to  claim 13 , further comprising desorbing the CO 2  from the absorption bed, and storing or further processing the desorbed CO 2 . 
     
     
       18. The method of capturing CO 2  during compressed air energy storage according to  claim 13 , wherein the compressed gas is expanded using a turbine. 
     
     
       19. The method of capturing CO 2  during compressed air energy storage of  claim 13 , wherein the expanded gas is used to cool the absorption bed during CO 2  absorption and to extract heat from the compressed gas stream after compression.